The overall objective of the proposed study is to elucidate the neural mechanism of action for hypothalamic and extra-hypothalamic control of anterior pituitary secretion. The classical techniques of orthodromic and antidromic identification, microelectrophoresis and the electrophysiological recording of extracellular action potentials will be combined to study the role of the nerve cell in endocrine function. More specifically, experiments will be conducted to establish the precise afferent and efferent connections of hypothalamic nerve cell that project toward the median eminence, and to determine transmitter pharmacology and receptor mechanism to the local deposition of the biogenic amines, ovarian steriods and releasing hormones, at the afferent postsynaptic membrane.